1. Field of Invention
The present invention relates to a micro-electro-mechanical system (MEMS) device and a method for making same, in particular to a method for making an MEMS device which is compatible with a CMOS (Complementary Metal-Oxide-Silicon) manufacturing process.
2. Description of Related Art
MEMS devices can be applied in many applications, such as in accelerometer, gyro sensor, and so on. It is preferred that the method for making an MEMS device is compatible with a standard CMOS manufacturing process so that transistor devices and circuitry can be made in the front-end process, to be integrated with the MEMS structure made in the back-end process.
U.S. Pat. No. 6,458,615 proposes a method for making an MEMS device which involves silicon etch. Its drawback is that it requires etching the silicon wafer, which is difficult to control.
U.S. Pat. No. 6,238,580 proposes a method for making an MEMS device which involves oxide etch. However, it does not explain the details as to how to manufacture the fine MEMS structure, and how to avoid damages to the MEMS structure during oxide etch.
The present invention proposes a solution to the above mentioned drawbacks in the prior art.